# Temperature and Humidity Chart



## LastClick (Jan 2, 2005)

I'm not sure how seriously this should be followed, just thought it was interesting. 
I borrowed this from another website and the chart below shows humidity adjustments that should be made for different temps.

Humidity levels are almost always referred in terms of Relative Humidity, the actual value that is important is the amount of water vapor present in a given volume of air, known as Absolute Humidity. As air will hold varying amounts of water vapor at different temperatures, no discussion
of humidification would be complete without a discussion of temperature and it's effect on absolute humidity. Relative humidity is an easily measured value that relates the measured humidity to the maximum humidity that is possible at that temperature. Thus, 70% RH at 70 ºF is not the same as 70% RH at 80 ºF. 

We are aiming to maintain the same amount of water (mgm/liter) around our cigars as seen at 70% RH at 70 degrees F (which is 13.15 mmHg water vapor pressure). 

So, to be able to know what is happening with our cigars at temperatures other than 70 degrees F, we must use a table of adjusted relative humidity values to make sure that our humidors keep our cigars in the peak of condition. 

Temperature, water vapor pressure and relative humidity required to equal 70% RH at 70 degrees (13.15mmHg).

Temp, Water Vapor Pressure, Relative Humidity 
66 16.37 80.33% 
67 16.95 77.58% 
68 17.55 74.93% 
69 18.17 72.37% 
70 18.79 70.00% 
71 19.45 67.61% 
72 20.11 65.39% 
73 20.81  63.19% 
74 21.51 61.13% 
75 22.25 59.10% 
76 23.00 57.17%


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## cigar_040 (Mar 10, 2006)

Very interesting indeed. Will have to look into more closely and ........

Thanks for posting


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## dayplanner (Dec 11, 1997)

This has been much discussed and debunked many, many times. RH is RH. That's why they call it "relative."

Unfortunately, this is bad science that just won't go away and keeps circulating and re-surfacing on the Web. Regrettably, even some vendors and B&Ms have been taken in by it.

I would caution anyone against storing their cigars at different humidity levels based on temperature and absolute humidity.

*Don't do it!*


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## JPH (Jun 30, 2006)

whiteboard said:


> This has been much discussed and debunked many, many times. RH is RH. That's why they call it "relative."
> 
> Unfortunately, this is bad science that just won't go away and keeps circulating and re-surfacing on the Web. Regrettably, even some vendors and B&Ms have been taken in by it.
> 
> ...


What he said......in a nut shell it's "*RELATIVE*" humidity..I'm no pro but your hygrometer (hopefully digital) adjusts automatically.


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## Desert Rat (Dec 19, 2005)

LastClick said:


> *We are aiming to maintain the same amount of water (mgm/liter) around our cigars as seen at 70% RH at 70 degrees F. *
> So, to be able to know what is happening with our cigars at temperatures other than 70 degrees F, we must use a table of adjusted relative humidity values to make sure that our humidors keep our cigars in the peak of condition.


Thank you for revisiting the effects of temp and humidity. Good info, however, the assumption that cigar storage is based upon 70/70 is not valid.

The collective experience I read and use for ambient moisture content of the air, is quite a bit lower than 70/70.

With plenty of exceptions, it would be fair to say people are tending towards 70 and a little below for temp and somewhere around 65 Rh. Thats what I have used with good results for the past few years.


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## dayplanner (Dec 11, 1997)

Desert Rat said:


> it would be fair to say people are tending towards 70 and a little below for temp and somewhere around 65 Rh. Thats what I have used with good results for the past few years.


 Myself included (65RH / 68 temp). Preferences for optimal RH vary. Some like 70. Some like 65. And some like a little below 65. But regardless of preference, RH should not be adjusted based on temp. It should be held as constant as possible based upon your RH preferences for optimal aging and smoking.


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## Baric (Jun 14, 2006)

good posts everybody! ive seen lots of these calculations adjusted for temperature etc being consiudered recently, best just to get a cigar oasis or the beads and trust in their magic IMO.


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## JohnnyFlake (May 31, 2006)

whiteboard said:


> Myself included (65RH / 68 temp). Preferences for optimal RH vary. Some like 70. Some like 65. And some like a little below 65. But regardless of preference, RH should not be adjusted based on temp. It should be held as constant as possible based upon your RH preferences for optimal aging and smoking.


I could not agree more, with what Hoyohio said. Living in the desert (Henerson, Nevada), it's very hard for me to maintain the same temp year-round. In the hottest summer months, even with heavy duty air conditioning, the temp in both my IglooDor and my Humidor hang around 72/74. During the rest of the year, the temp, in both, hangs around 68/70. However, I strive to maintin an RH of 65% all the time! It works very well for me.

JohnnyFlake


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## ghostrider (Oct 30, 2005)

> Temp, Water Vapor Pressure, Relative Humidity
> 66 16.37 80.33%
> 67 16.95 77.58%
> 68 17.55 74.93%
> ...


Based on the readings on my hygro vs this chart, it's easy to see this is not necessarily true. I can maintain 65% RH, regardless of the temp (thanks to my beads!).


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## Ermo (Jun 3, 2006)

It's not true. 

According to the chart if you stored your smokes at, say, 60 degrees, which I do, you would want around 90% relative humidity!! No way. And if you stored your smokes at 76f would you feel comfortable with 57% humidity?

Like said above, relative is just that, relative. That chart is hazardous for the health of your smokes.


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## LastClick (Jan 2, 2005)

I have to agree with you guys on the subject. I keep the RH around 65-67% regardless of temp fluctuation and my sticks have been fine. Just thought adjusting RH was an interesting observation or opinion, but I don't think I would raise the RH to 80-90 for a low 60 something temp. :hn

The sad thing is the chart came from a reputable vendor.


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## Ermo (Jun 3, 2006)

You should tell the vendor not to publish that, could ruin a noob's first sticks if they read that and follow it.


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## mdman (Sep 11, 2003)

This should not be used at all!

Relitive humidity already makes up for this chart.. which is why its called "Relitive Humidity"
and this is what your Hygrometer reads..

There is a Big difference between Humidity and Relitive Humidity.
If a vendor gave you this, they dont know what they are talking about.


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## LastClick (Jan 2, 2005)

The chart is posted on their website.

Also, I found more info on relative humidity: http://en.wikipedia.org/wiki/Relative_humidity

I do still think that as long as the temp is 70 or below and humidity is in the 60-70% range, (based on personal preference), the smokes will be fine.



mdman said:


> This should not be used at all!
> 
> Relitive humidity already makes up for this chart.. which is why its called "Relitive Humidity"
> and this is what your Hygrometer reads..
> ...


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## BobM (Dec 1, 2018)

Actually, the chart is spot on. This is called a psychrometric chart (just Google this if you don't believe it) and provides the temperature and RH needed to maintain a certain water content in the air (absolute humidity). With a humidor you are trying to maintain a specific water content in the cigar for the ideal smoke. I live in northern Arizona and I can absolutely tell if the water content of the cigars are low by the cracking of the wrapper when I cut the cigar and the hot dry harsh smoke when I'm smoking the cigar.

I have a wine humidor that I use as my cigar humidor. But the temperature control doesn't allow me to set the temp above 65 degrees (the actual temperature in the humidor when I set it there averages around 67 degrees). And yes, I set my RH to 78% because I want my cigars to have the same water content as when I bought them. I use a Fluke 971 meter to measure temperature and humidity in the humidor (a bit pricey, but so are cigars and I wanted a meter that was calibrated to a specific standard and would stay that way). I use an electric humidifier to maintain humidity (you go through a lot of distilled water in a dry climate) and you absolutely cannot trust the meter on the humidifier. I had to play with the humidifier settings quite a bit using the Fluke meter before I was able to get spot on humidity. I live in a very dry climate and get splendid results with my setup.


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## ras_oscar (Aug 30, 2015)

For me the biggest take away is to calm down and don't worry about humidity swings when the temp is moving seasonally. When the humidity is 65 it's time to add moisture. Other than that I don't worry abu=out the temp, and I certainly don't adjust my humidity setpoint based on it.


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## Joe Sticks (May 31, 2016)

On another website a fellow with a scientific bent who builds cigar storage units pointed out that moisture content within the cigars actually rises with lowered temperature. 
This makes sense. With lower temps, air is less able to hold moisture & that moisture goes into the cigars. This is within a closed system.

Sent from my iPhone using Tapatalk Pro


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## ras_oscar (Aug 30, 2015)

Joe Sticks said:


> On another website a fellow with a scientific bent who builds cigar storage units pointed out that moisture content within the cigars actually rises with lowered temperature.
> This makes sense. With lower temps, air is less able to hold moisture & that moisture goes into the cigars.
> 
> Sent from my iPhone using Tapatalk Pro


 yes, or condenses out as liquid moisture. ( not a good thing)


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## scott1256ca (Jan 4, 2017)

> Actually, the chart is spot on. This is called a psychrometric chart (just Google this if you don't believe it) and provides the temperature and RH needed to maintain a certain water content in the air (absolute humidity). With a humidor you are trying to maintain a specific water content in the cigar for the ideal smoke.


Well, you just said it yourself. You are trying to maintain a specific water content in the cigar. The chart referenced is about the water content of the air. Not the same at all. 
I think what you are after is equilibrium moisture content for various temps and RH. I got this chart from 
https://burleytobaccoextension.ca.uky.edu/files/aeu-93_burley_curing_technology.pdf
It tells me that if I wanted to keep a moisture content in my cigars of exactly 14%, and my temperature was going from to change from 65F to 80F then I would have to keep an RH of 64% at 65F and change the RH to 68% at 80F (14% on the vertical axis from 65 to 80 curves and looking at the horizontal axis at the bottom) which is about 1.25% RH change for a 5 degree change in temp. That small a RH change would be difficult to do accurately. I think it's easier to just get the RH you want and leave it there and don't mess with it when the temp changes. 78% RH looks way too high to me, but if that is how you like your cigars, who am I do judge?


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## UBC03 (Nov 18, 2015)

Ooh,ooh,ooh .. I can help.. 

If you look at your hygro and it says 58%.. spritz you kl.

67%+ hit the kl with a hair dryer for few seconds (on low or it'll be a mess..Trust me) 

If it says 60- 64 ..grab a smoke. 

If the temps is in the 60-68° range.. Grab a smoke

Unless you're planning to age your cigars and sell em ten years from now for top dollar and want to say "maintained precisely at 65/65 for a decade". It's no biggie..

Remember it's tobacco not newborns. 

My favorite part of this hobby is smoking cigars.. NOT MAINTENANCE.. It's just a necessary evil to enjoy a cigar.

Sent from my SM-G925V using Tapatalk


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## TexaSmoke (Apr 13, 2018)

UBC03 said:


> Ooh,ooh,ooh .. I can help..
> 
> If you look at your hygro and it says 58%.. spritz you kl.
> 
> ...


This has become my norm. As long as temps and RH are somewhere in the 60s, we are cleared for takeoff and I don't even look at it until I go to grab another stick.


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